This invention relates to a vehicle wheel traction device and more particularly to a conveniently removable traction apparatus for attachment to a tire carrying wheel mounted on a vehicle.
Tire chains are presently used on vehicles as a means to establish greater traction between the drive wheels of a vehicle and the terrain, especially on icy and snow covered roads. The disadvantages of chains are well known, the utmost being the difficulties of mounting and removing, and their relative ineffectiveness in providing traction on ice and hard packed snow. Moreover, each time the snow thaws or is cleared from the streets the chains have to be laboriously removed and stored inasmuch as they are not only noisy but are liable to injure the tires when used on dry pavement.
In order to overcome these and other objections to tire chains, various other traction devices have been designed. These devices have all had certain objectionable features, however, and none has been commercially successful. One such device utilized elongated, rigid spikes or gripping arms which were fastened to a face of the vehicle wheel and project radially outwardly beyond the periphery of the wheel to engage the surface of the road. This type of device has excellent gripping qualities and provides effective traction under even the most difficult driving conditions. Unfortunately, however, the rigid arms dig into and damage the pavement and, in addition, are frequently broken off or bent by obstacles in the roadway such as stones or railway tracks. Moreover, the gripping members used in this type of traction device are either permanently attached to the wheel and can not be removed when not in use, or they are mounted on the wheel in such a manner that their removal is extremely difficult.
Spikes or studs on tires are generally permanently mounted during winter months and have certain well known disadvantages in normal driving conditions such as limiting driving speed, noise, wear to the road surface and so on. As to wearing of road surfaces, stud equipped tires are often disallowed on selected roadways.
The above systems all have the disadvantage of being relatively unhandy to mount and dismount from the vehicle.
Another tire mounted traction device which appears to be easier to mount and dismount on a vehicle is shown in U.S. Pat. No. 2,986,190 to Lamb which shows a mounting disc that may be mounted on the vehicle during periods of inclement weather, while the individual traction members are removable from the disc so that they need be mounted only when additional traction is needed. Each traction member is a coil spring threadedly connected to the disc. Of course the greater the number of traction members used, the greater the inconvenience of mounting and dismounting the traction members. Additionally, all the lug nuts must be removed simultaneously to install the disc.
U.S. Pat. No. 3,861,752 shows an anti skid device for attachment to vehicle wheels by means of lug bolts and supported by the vehicle wheel. Traction members are moved between "stored" and "use" positions by means of a folding linkage. The use position moves the traction member to a point beneath the vehicle tire. Such a device wound tend to wear tires and would no doubt be noisy, the effect being similar to chains. Again all lug nuts would have to be removed simultaneously for mounting the apparatus.
Ceccucci U.S. Pat. No. 3,482,880 shows a device similar to Lamb in that individual traction members are attached to a disc, but have a stored position on the disc. Each traction member is biased by an individual spring into contact with the terrain. This would be an expensive apparatus to build. All lug bolts need be removed simultaneously for mounting the apparatus on a wheel.
Williams U.S. Pat. No. 2,494,850 shows a non-skid device mounted on a vehicle wheel although it is not apparent from the patent as to exactly how this is done. However, it appears that the device is mounted to apertures in the disc portion of a wheel which presumes that such apertures exist in all wheels. A rather complicated mechanism pivotally grips the side of each wheel and has a traction element that extends to the side of the tire. This apparatus would appear to be flimsily designed for its intended use.
U.S. Pat. No. 1,890,872 shows a device for duplex truck wheels having individually spring loaded traction members.
Fletcher U.S. Pat. No. 3,911,985 has a disc positioned on a vehicle axle which supports a plurality of traction prongs pivotally attached to a wheel and slidable on the disc. A control rod operable from the interior of the vehicle arcuates the rod to permit rotation of the disc. This device is extremely complex and would require major modification of a vehicle implement for use.
Each of the devices described above for providing additional emergency traction on a vehicle wheel has disadvantages as to effectiveness, simplicity of construction and thus cost, as well as inconvenience to install and operate.
It is therefore an object of the present invention to provide a new and improved vehicle traction apparatus which is simple in construction, effective in all types of weather and terrain conditions, and convenient to install and remove.